Maintenance of sulfonylurea responsiveness in NIDDM. Randomized double-blind study of intermittent glyburide therapy

To assess the effectiveness of intermittent administration of sulfonylurea (glyburide) to patients with non-insulin-dependent diabetes mellitus (NIDDM).

A randomized, double-blind, prospective trial compared daily administration with intermittent administration of glyburide to patients who initially responded to the drug. Twenty-eight of 60 patients with NIDDM achieved the predetermined improvement in plasma glucose concentration on glyburide therapy. These 28 responders were enrolled into a 16-wk trial of daily versus intermittent (2 wk on, 2 wk off) glyburide treatment. Laboratory assessment of glycemic control and insulin secretion in fasting and 2-h postprandial states was done every 2 wk.

Patients on continuous glyburide therapy maintained their glycemic control throughout the study. In contrast, patients on the intermittent schedule lost their glycemic control immediately after being placed on placebo. Despite a significant response to each sulfonylurea pulse, these subjects never regained their baseline glycemic levels. Their fructosamine and HbA1c concentrations deteriorated and remained significantly higher than those of the continuously treated subjects.

Results suggest that administration of glyburide on an intermittent basis after a 2-wk drug-free period to patients initially rendered responsive to sulfonylurea therapy is without clinical merit.